This invention relates to shipping and storage containers. More particularly, it relates to containers in which the base of the container serves as a reusable pallet.
Various container designs have been employed to ship and store industrial goods. In many instances the containers are stored in large warehouse facilities where they are moved from one location to another by forklift trucks or the like. One commonly used container incorporates a corrugated sleeve which is nailed to a conventional wooden pallet. The sleeve forms the side walls of the container and the pallet serves as its bottom. The use of the wooden pallets, however, has some drawbacks. For example, they are subject to breakage and thus are not reusable over an extended period of time. Wooden pallets also take up a considerable amount of valuable floor space in the warehouse when they are not in use.
In an effort to solve some of the problems with the wooden pallets, reusable plastic pallets have been employed with some degree of success. Such pallets have been combined with corrugated sides and a plastic cover to form a container. The plastic pallet and cover are reusable and may be more compactly stacked when not in use, thereby providing significant advantages over the use of conventional wooden pallets. U.S. Pat. No. 4,254,873 to Cook III et. al. is a representative example of such a composite container design.
These composite container designs also have their drawbacks. The edges of the sleeve merely rest in grooves in the pallet and cover in most of the known designs. Consequently, some additional means must be provided to hold them together prior to shipping. Generally the pallet, corrugated sleeve, and cover are banded together by steel bands or cords encircling the three components. This banding process introduces an additional expense in both time and money since the container must not only be bound prior to shipping but it also must be unbound before the containers contents can be removed.
As previously noted, warehouse space is valuable. It is therefore desirable to be able to stack these composite containers on top of one another in order to conserve space. In such instances the lower containers often experience substantial compressive forces from the weight of the upper containers. These compressive forces are generally transferred by the sides of the container downwardly to the peripheral edges of the pallet. In the typical prior art designs, legs or spaces providing clearance for the skids of the forklift are spaced inwardly of the peripheral edges of the pallet. The compressive loads applied through the sides of the container are often sufficient to deform the peripheral portions of the pallet outside of the supporting legs or spacers. Such deformation may damage the pallet to such an extent that it is not readily reusable.
The structural rigidity of these pallets may be enhanced by using more plastic material or by using special reinforcing means but such measures unduly increase manufacturing costs.
The present invention is directed to solving one or more of these problems.